Process of making stone-concrete structures.



c. F. MORRILL.

PRdoEss 0? MAKING STONE GONORETE STRUCTURES.

APPLICATION FILED AUG. 12, 1905.

963,734. Patented July 5,1910.

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0-. F. MOBRILL.

PROCESS OF MAKING STONE OONORETB STRUCTURES.

APILIOATION FILED Aim-12, 196a.

Patented July 5, 1910.

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CHARLES F. MORRILL, OF BOSTON, MASSACHUSETTS.

PROCESS OF MAKING STONE-CONCRETE STRUCTURES.

Specification of Letters Patent.

Patented July 5, 1910.

Application filed August 12, 1905. Serial No. 273,875.

To all whom it may concern:

Be it known that I, CHARLES F. MORRILL, of Boston, in the county ofSuffolk and State of Massachusetts, have invented certain new and usefulImprovements in Processes of Making Stone-Concrete Structures, of whichthe following is a specification.

The object of my invention is to make stone concrete of maximum strengthin tension, compression and shear and that is more effective incombination with metal, as in steel-concrete girders, beams and floorconstruction and that is entirely free from voids with which stoneconcrete is more or less honeycombed by the present method ofmanufacture.

Stone concrete made by my improved method insures a dense and solidconcrete, of uniform and maximum strength, accord ing to the materialused.

I will now describe the present method of making stone concrete and thedisadvantages and objections arising therefrom, that my improved processmay be more apparent.

According to the present method, predetermined proportions of Portlandcement, sand, water and crushed stone, or other aggregates, are mixedtogether and molded, as a whole, within a centering form or mold, withthe object of producing a solid concrete body, as a girder, beam, orwall in building construction; but in practice it is found that thisobject is not attained. There is a tendency to use too large aproportion of crushed stone, but when such is not the case, it is foundthat when the concrete as now made is molded and tamped within thecentering form, or mold, that parts of the crushed stone come in contactwith each other at many points in such shape as to form intersticeswithin the concrete body and between the exterior portion of theconcrete body and the centerin form, or mold, thus proportionatelyreduclng the strength of the molded body; and when steel tension orcompression chords are used, as in girder and beam construction, thecrushed stone in contact with the metal forms interstices and prevents aclose union between the plastic portion of the concrete and metal; andwhen the metal is located in the lower part of the molded body, near thebottom of the centering form, or mold, as required in small beams andlike construction, the crushed stone incontact with the metal tensionchords and centering mold forms interstices that prevents the plasticportion of the concrete from firmly uniting with the steel chord at allpoints with consequent diminution of strength in the steelconcretegirder or floor beam.

It is-a well-known fact, among workers in concrete construction, thatconcrete is not uniform in strength with the same care and attention inmanufacture and when like material is used, which can be readilyaccounted for by the irregular formation of voids within the concretebody by the crushed stone, with consequent loss of strength in concreteconstruction, as herein described. And further, according to the presentmethod of making concrete, the crushed stone being the larger bulk, theplastic portion of the concrete separates and adheres to the stone andoften becomes partially set before it can be molded within the centeringform, or mold, thus reducing the strength of the molded concrete. Noneof these objections arise in my process of manufacture, which I will nowproceed to describe.

My invention consists of making stone concrete by first mixing togetheraccurate proportions of Portland cement, or other cementitious material,sand and water, thus making a plastic composition of the properconsistency, which is then molded in single layers within the requiredcentering form, or mold, as for a girder, beam or in wall construction,then crushed stone, or other aggregate of similar nature and purpose,are tamped within the plastic material to the extent that no morecrushed stone or other aggregate can be embedded therein; the plasticmaterial being displaced by the crushed stone or other aggregateexcepting that portion remaining between the crushed stone that uniteswith it and forms a solid mass of stone concrete; then another layer ofplastic material is added and the process repeated until the centeringform, or mold, is entirely filled with a solid mass of stone concrete ofthe form desired By this method of manufacture the plastic materialunites with and envelops the steel chords, as used in girder, beam andfloor construction, while the later addition of crushed stone or otheraggregate displaces the plastic material only to the extent of the sizeof the solid aggregate embedded therein; the plastic material firmlyuniting with the crushed stone, thus forming a solid body of stone'mold, for a girder or floor beam for building construction. Thiscentering form, or mold, is shown with beveled sides, but may be squareor of any desired shape, and is designated by the letter a. The letter 6represents space within the centering form wherein the concrete ismolded. The letter (Z represents a steel tension chord located withinthe centering form a.

Figs. 2 and 2 represent in sections the centering form, or mold, a withthe addition of a layer of plastic material 0 molded therein; theplastic material 0 partially enveloping the steel tension chord 03.

Figs. 3 and 3 represent in sections the centering form, or mold, a withthe plastic material molded therein, as described in Figs. 2 and 2 withthe further addition of crushed stone or other aggregate embedded andtamped within the plastic material, forming the first layer of stoneconcrete which is denoted by the letters 0 0.

Figs. 4: and 4* represent sections of a finished stone concrete girderor floor beam, with a concrete floor homogenous therewith, as shownafter the concrete had set and the centering form been removed, and wasformed by adding layer after layer of plastic material with crushedstone or other aggregate embedded in each layer, as the work progressed,until the centering form was filled and the full size of the girderdeveloped, according to my improved method, and is denoted by theletters G C.

Fig. 5 represents a brick centering form, or mold a, inclosing a steelcolumn 6 used in building construction.

Fig. 6 represents the centering form, or mold a, shown in Fig. 5 with alayer of plastic material 0 molded therein.

Fig. 7 represents the centering form, or mold a, shown in Figs. 5 and 6,but entirely filled with stone concrete, formed by molding layer afterlayer of plastic material within the centering form, with crushed stoneembedded successively in each layer, according to my improved method,the solid concrete inclosing and firmly uniting with the steel column,which it aids in support.

Figs. 8, 9 and 10 represent centering forms, or molds a, designed forwall construction where the same method of concrete manufacture isshown.

Figs. 11, 12 and 13 represent my, improved method of concretemanufacture, as applied to pile foundation.

I will again call attention to the advantage of my process in themanufacture of stone concrete. I have already stated that stone concretemade by my improved method insures a dense and solid concrete of uniformand maximum strength, according to the material used and as cement isthe life of stone concrete so is the strength of stone concrete inproportion to the cement used. A good, cementitious, plastic materialfor making stone concrete, according to my process, is composed of onepart good Portland cement and three parts sharp grain sand thoroughlymixed with Water to the consistency of mortar as used for plasteringceilings andwalls in building construction. The plastic material is thenmolded in a centering form or mold in layers for columns, girders,floors, or other construction with crushed stone successively embeddedin each layer, and forming a solid body of stone concrete. Such stoneconcrete may be safely used at 100 lbs. per inch in comprcssion, and inlike manner with one part Portland cement and 2:} parts sand at 500 lbs,and with one part Portland cement and two parts sand at 600 lbs., andwith one part Portland cement and one and one-half parts sand at 700lbs., and with approximately proportionate resistance to compres sivestrains according to the proportion of cement used. I will mention thatthe best results are obtained in the manufacture of stone concrete byhaving the crushed stone clean and wet when ready for use, and thisresult is easily obtained by my method of embedding clean-washed crushedstone in the cementitious, plastic material, as described. I will alsomention that in shallow, stone concrete beams, floors and otherconstruction, either with or without the use of steel, that only asingle layer of plastic material may be required, with crushed stone orother aggregate embedded therein, to develop the desired size.

Having described my invention I now present the following claims forLetters Patent:

1. The herein described process of manufacturing molded stone concrete,which consists in first making a cementitious, plastic material,composed of relative proportions of cement, sand and water, thoroughlymixed to a plastic consistency, and then molding this material within acentering form or mold in a layer of the required thickness; and thentamping crushed stone or other aggregate into this layer ofcementitious, plastic material to the determined capacity of saidmaterial; and then tamping and compressing the combined mass andallowing it to harden until it becomes a all substantially as terial tothe determined capacity of said material, and then adding another layerof l this material and tamping crushed stone or other aggregatethereinto, as before, and repeating the process until the molded body ismade of the required size; and then tamping and compressing the combinedmass and allowing it to harden until it becomes a solid stone concretebody, all substantially as herein set forth.

In testimony whereof I have affixed my signature, in presence of twoWitnesses.

CHARLES F. MORRILL.

Witnesses:

A. W. HARRISON, ARTHUR H. BROWN.

